The invention relates to a disposable injector with a housing in which or on which are arranged, in each case at least in some areas, at least one mechanical spring energy reservoir, at least one cylinder/piston unit that can be filled at least temporarily with active substance, at least one piston-actuating ram and at least one trigger unit, wherein the piston-actuating ram is positioned between the spring energy reservoir and the piston of the cylinder/piston unit, wherein the spring energy reservoir comprises at least one pretensioned spring element, wherein the spring-loaded piston-actuating ram is supported on the housing in a releasable manner.
DE 10 2007 031 630 A1 discloses, among other things, an injector of this type. With the exception of the mechanical spring of the spring energy reservoir, almost all the components of the injector are produced expensively from plastics by injection moulding. Components that are subject to high mechanical loads are additionally reinforced with glass fibres.
DE 10 2007 008 369 A1 discloses a one-way injector with a housing in which or on which, in each case at least one cylinder-piston unit which can at least at times be filled with an effective medium, at least one piston operating plunger and at least one trigger unit are arranged, wherein the spring energy store comprises at least one pre-tensioned spring element and wherein at least a part of the piston operating plunger is positioned between the spring-energy store and the piston of the cylinder-piston unit. The spring-charged piston operating plunger includes at least one pull rod which has at least one support surface in the area of its rear end. On the support surface or surfaces locking elements abut the housing whose locking position is secured by a trigger element which is retained in a locking position. The trigger element has a release position which causes the release of the locking elements.
EP 0 518 416 A1 discloses an injection device comprising a glass ampoule with an injection canula and a piston which is slowly pushed into the glass ampoule by a pre-tensioned spring in order to eject the injection liquid contained in the glass ampoule.
Therefore, the problem addressed by the present invention is that of developing a disposable injector of modular design which, with a small overall size, comprises only a small number of components and, while being easy to handle and inexpensive to produce, ensures safe storage and operation.